Other Car Rental Programs/Partners (ie. Alamo, Enterprise, Sixt) - Reservation and Rate altered by the system ?

I tried to check a reservation I had made online recently. The website gave me the error message "Additional driver(s) not supported by WEB".

The reservation was for me as the main renter (over 25) and 1 additional driver (under 25). The original reservation listed a surcharge for additional drivers and one for drivers under 25.

Now I call Alamo and they tell me in their system, they now show a different rate than the one I was quoted, and the surcharge for the person under 25 is not included in that price. The total would come to around $300 more than what I was quoted.

Alamo is supposed to honor my original reservation, right ? I do have a printout showing all details.

I just experienced the same thing with a rental I returned to LAS yesterday. My original quote before the website "upgrade" as $130. After the upgrade, my res showed $135. Then the actual rental was $152. Then the return receipt showed $147. Had to have it corrected back to $130. I was lucky to have the original e-mail confirmation.

PS: This was also a Quicksilver rental, which I'm fast learning doesn't mean much. The only "Quicksilver" part of the rental was the fact that the Century I got was silver. Can't wait for my next rental. Have fun!